<script setup lang="ts">

import { computed, ref, watch } from 'vue'

// 定义水果对象的类型
interface Fruit {
  id: number
  icon: string
  isChecked: boolean
  num: number
  price: number
}

// 默认水果列表
const defaultList = ref<Fruit[]>([
  {
    id: 1,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/ll.png',
    isChecked: true,
    num: 2,
    price: 6,
  },
  {
    id: 2,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/smt.png',
    isChecked: false,
    num: 7,
    price: 20,
  },
  {
    id: 3,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/tg.png',
    isChecked: false,
    num: 3,
    price: 40,
  },
  {
    id: 4,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/xg.png',
    isChecked: false,
    num: 10,
    price: 3,
  },
  {
    id: 5,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/yl.png',
    isChecked: false,
    num: 20,
    price: 34,
  },
])

const fruitList = localStorage.getItem('list')===null?
ref<Fruit[]>(defaultList.value):ref<Fruit[]>(JSON.parse(localStorage.getItem('list')||'[]'))

watch(fruitList,()=>{
  localStorage.setItem('list',JSON.stringify(fruitList.value))
},{deep:true,immediate:true})


// 删除水果
const deleteFruit = (id: number) => {
  // 通过 id 进行删除数组中的 对应项 → filter(不会改变原数组，需重新赋值)
  fruitList.value = fruitList.value.filter(item => item.id !== id)
}

// 减少水果数量
const decreaseFruit = (id: number) => {
  // find 查找到当前元素
  const activeItem = fruitList.value.find(item => item.id === id)
  // && 短路运算
  // activeItem && activeItem.num--
  if (activeItem) {
    activeItem.num--
  }
  // 补充：findIndex 写法
  // const activeIndex = fruitList.value.findIndex(item => item.id === id)
  // fruitList.value[activeIndex].num--
}

// 增加水果数量
const increaseFruit = (id: number) => {
  const activeItem = fruitList.value.find(v => v.id === id)
  // activeItem && activeItem.num++
  if (activeItem) {
    activeItem.num++
  }
}

//通过计算属性，计算全选状态
const isAllSelected = computed({
  get() {
    return fruitList.value.every(item => item.isChecked)
  },
  set(value) {
    fruitList.value.forEach(item => {
      item.isChecked = value
    })
  }
})

// 计算选中的水果列表
const selectedFruitLis = computed(() => {
  return fruitList.value.filter(item => item.isChecked)
})
// 总个数：找到选中的，累加个数即可
const totalCount = computed(() => {
 return selectedFruitLis.value.reduce((acc, item) => acc + item.num, 0)
})
// 总价
const totalPrice = computed(() => {
  return selectedFruitLis.value.reduce((acc, item) => acc + item.num * item.price, 0)
})

</script>

<template>
  <div class="app-container" id="app">
    <!-- 顶部banner -->
    <div class="banner-box">
      <img
        src="https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/sg_top.png"
        alt=""
      />
    </div>
    <!-- 面包屑 -->
    <div class="breadcrumb">
      <span>🏠</span>
      /
      <span>购物车</span>
    </div>
    <!-- 购物车主体 -->
    <div v-if="fruitList.length" class="main">
      <div class="table">
        <!-- 头部 -->
        <div class="thead">
          <div class="tr">
            <div class="th">选中</div>
            <div class="th th-pic">图片</div>
            <div class="th">单价</div>
            <div class="th num-th">个数</div>
            <div class="th">小计</div>
            <div class="th">操作</div>
          </div>
        </div>
        <!-- 身体 -->
        <div class="tbody">
          <div v-for="item in fruitList" :key="item.id" class="tr active">
            <div class="td">
              <input type="checkbox" v-model="item.isChecked" />
            </div>
            <div class="td"><img :src="item.icon" alt="" /></div>
            <div class="td">{{ item.price }}</div>
            <div class="td">
              <div class="my-input-number">
                <button  :disabled="item.num <= 1" @click="decreaseFruit(item.id)" class="decrease">-</button>
                <span class="my-input__inner">{{ item.num }}</span>
                <button @click="increaseFruit(item.id)" class="increase">+</button>
              </div>
            </div>
            <div class="td">{{ item.num * item.price }}</div>
            <div class="td">
              <button @click="deleteFruit(item.id)">删除</button>
            </div>
          </div>
        </div>
      </div>
      <!-- 底部 -->
      <div class="bottom">
        <!-- 全选 -->
        <label class="check-all">
          <input type="checkbox" v-model="isAllSelected" />
          全选
        </label>
        <div class="right-box">
          <!-- 所有商品总价 -->
          <span class="price-box"
            >总价&nbsp;&nbsp;:&nbsp;&nbsp;¥&nbsp;<span class="price"
              >{{totalPrice}}</span
            ></span
          >
          <!-- 结算按钮 -->
          <button class="pay">结算( {{totalCount}} )</button>
        </div>
      </div>
    </div>
    <!-- 空车 -->
    <div v-else class="empty">🛒空空如也</div>
  </div>
</template>

<style scoped>
@import './style/inputnumber.css';
@import './style/index.css';
</style>
